How to use the calculator :

1. Work top-to-bottom and fill **every** drop-down to the best of your knowledge.  

2. Can’t decide between “light” and “moderate”? Choose the **higher** damage level.

3. Checkboxes are optional; tick only what you clearly see.  

4. Press Calculate to see Grade and Summary.

5. Scroll down to watch YouTube videos if you want to learn more about Grading Scale or what is considered "light" or "moderate" fold, etc.

DISCLAIMER: This tool gives a private and unofficial estimate based on publicly available PCGS standards (not endorsed by PCGS). It is NOT a guarantee of any third-party grade, value, or marketability. Always consult a professional grading service for final certification.

How it works:

1. Click to upload a single JPG (better the image, more accurate the results).

2. Select "Overall Wear" level from provided options (very important).

3. A.I. then uses OpenCV.js (WebAssembly) to scan the image in 3 ways:  

-HSV color filter → finds yellow/brown stains  

-Canny edge + Hough lines → counts tears & heavy creases  

-Contour finder → measures dark “holes”  

4. Each flaw gets a 0-10 damage score; the average is converted to numerical grade range as below.  

Damage Index    Suggested Grade Range

 0–5               67–70

    6–12   64–66

 13–20      60–63

 21–30     55–58

 31–45     50–53

 46–60     40–49

 61+                          ≤35

5. Laplacian blur checks photo sharpness → confidence %.

6. Final output is Estimated Grade Range using Sheldon 0-70 scale.

DISCLAIMER: This tool uses A.I. to give an unofficial estimate based on single image and can be erroneous. This is a work-in-progress and may be inaccurate! Appreciate your understanding.